Arabian Journal of Chemistry最新文献

A novel bio-covalent organic framework (COF: TpPa-SO₃H/Lignin) based on TpPa-SO₃H and lignin from lignocellulose was synthesized for chromium (Cr(VI)) remediation in this study. Results showed that TpPa-SO₃H/Lignin had a highest adsorption capacity at the range of 5 ∼ 75 mg/L Cr(VI) under 10 mg/L dosage, in which 100 % Cr(VI) could be removal within 120 min. Likewise, the introduction of lignin improved the visible light response range, charge separation and photogenerated carriers, thereby improving the photocatalytic efficiency of Cr(VI) by TpPa-SO₃H/Lignin. The highest photocatalytic efficiency of TpPa-SO₃H/Lignin (98.56 %) was observed at the acidic conditions. ESR result shows that e- and ·O₂^– are generated and played an important role during the photocatalytic reaction, while the contribution of ·OH to Cr(VI) photoreduction is negligible. This study presents a sustainable and efficient approach to mitigating Cr(VI) pollution. It opens up avenues for further exploration of lignocellulose-derived materials in environmental applications and highlights the potential of COFs in addressing heavy metal contaminants.

This study evaluates the application of supercritical carbon dioxide chelation extraction technology for treating heavy metal ions (Zn²⁺ and Cr³⁺) in drilling fluid waste. Through a combination of experimental and molecular dynamics simulation methods, the influence of extraction parameters (temperature, pressure, duration, and chelating agents) on the extraction efficiency are investigated. Findings show that increased duration and pressure significantly improve extraction efficiency, while temperature has a complex effect, initially increasing efficiency but plateauing and slightly decreasing at higher temperatures. The optimum extraction condition with pressure of 220 bar, temperature 348.15 K and an extraction duration of 70 min using ethylene diamine tetraacetic acid (EDTA) as the chelating agent has been determined. Importantly, molecular simulation analysis revealed that citric acid outperforms EDTA in terms of Zn²⁺ and Cr³⁺ aggregation by forming larger aggregates with greater numbers of molecules while reducing overall aggregate count. Furthermore, optimization of extraction pressure in the EDTA system shows potential benefits. These results suggest that supercritical carbon dioxide chelation extraction technology has strong potential for environmentally friendly and reliable waste management in the drilling industry. This study represents a significant step forward in developing sustainable solutions for heavy metal removal from drilling fluid waste.

Background

Schisandra chinensis (Turcz.) Baill (Schisandraceae) and Acorus tatarinowii Schott (Araceae Juss) (Sc-At) are two traditional Chinese medicinal herbs that are widely used in the treatment of neurological disorders such as insomnia. In our previous study, we found that Sc-At could improve the therapeutic efficacy of Alzheimer’s disease by affecting aromatase activity and estrogen levels, among other pathways.

Material and methods

In this study, first, the ameliorative effect of Sc-At on cognitive dysfunction in Alzheimer’s disease model rats was verified by Y-maze test together with Elisa assay. Second, fecal untargeted metabolomics analysis was performed using a UPLC-Q-TOF/MS-based metabolomics approach. 16S rDNA sequencing was utilized to screen the differential flora between groups, and linear discriminantan alysis effect size (LEfSe) was used to find the target flora. Finally, Spearman correlation analysis was combined to find the relationship between differential flora and differential metabolites in feces.

Results

(1) The results of Y-maze test and Elisa assay indicated that Sc-At could improve the cognitive dysfunction of AD model rats. (2) Metabolomics results showed that fecal metabolite levels were significantly different from those of rats in the blank group, and 18 potential biomarkers in feces were screened, mainly affecting linoleic acid metabolism, steroid hormone biosynthesis, sphingomyelin metabolism, riboflavin metabolism, etc. The 16S rDNA results showed that the abundance and diversity of intestinal flora in AD rats were destroyed, and the Sc-At treatment was able to reverse these changes. (3) Spearman’s correlation analysis showed a significant correlation between differential metabolites in feces and intestinal flora, further suggesting that Sc-At treats Alzheimer’s disease through the gut-brain axis.

Conclusions

In this study, we explored the mechanism of Sc-At in the treatment of Alzheimer’s disease by integrating fecal untargeted metabolomics and 16S rDNA gene sequencing, and the results showed that Sc-At exerts therapeutic effects on Alzheimer’s disease by improving the intestinal flora and related metabolic pathways.

Industrial wastewater treatment increasingly relies on membrane separation, with ceramic membranes offering many advantages such as thermal stability and pH resistance. The resistance of ceramic membranes to extreme pH conditions indicates their ability to maintain structure and performance when exposed to highly acidic or alkaline environments. A high-permeability ceramic nanofiltration membrane was developed, boasting excellent rejection rates through a multilayer asymmetric design. Initially, two tubular porous supports, mullite and mullite-alumina, with a weight percent of 50, were fabricated using the extrusion method. Subsequently, a colloidal sol of titania (TiO₂) and titania-zirconia (TiO₂- ZrO₂) was prepared via the sol–gel method and coated on the ceramic supports using the dip-coating method. After analyzing the membrane microstructure using SEM, XRD, and BET, the efficiency of the membranes in treating synthetic oily wastewater was evaluated. The results underscore the significant impact of the Donnan exclusion mechanism on the rejection of nanofiltration (NF) membranes. An increase in pressure led to a rise in rejection rates up to 7 bars. The Chemical Oxygen Demand (COD) rejection for mullite-titania zirconia (MTZ) and mullite-alumina-titania zirconia (MATZ) membranes was 98.65 % and 98 %, respectively. The pure water permeability test results for mullite and mullite-alumina supports, as well as MTZ and MATZ membranes, were recorded as 254, 382, 70, and 89 L bar^-1m^-2h⁻¹, respectively.

This work presents an advanced automated monolithic C18 pipette-tip solid-phase extraction (PT-SPE) method seamlessly integrated with liquid chromatography-tandem mass spectrometry (LC-MS/MS) for precise therapeutic drug monitoring of eleven tyrosine kinase inhibitors (TKIs) in biological samples. Commercially available MonoTip C18 columns facilitate superior extraction efficiency and selectivity from complex biological matrices owing to their large surface areas and enhanced mass transfer capabilities. The sample preparation process, conducted by aspirating and dispensing solutions using a pipettor, completes the overall extraction process within 3 min. The method validation demonstrated excellent linearity within the range of 0.2/0.5/0.8 to 200 ng/mL, with detection limits ranging from 0.049 to 0.206 ng/mL. The method exhibited outstanding accuracy and precision, with intraday relative recovery rates ranging from 96.3 % to 115.0 % and interday recovery rates ranging from 95.0 % to 115.7 %, with coefficient of variation values consistently below 13.8 %. The proposed method is distinguished by its exceptional efficiency, reduced solvent use, enhanced environmental sustainability, and streamlined automation—key advantages in the realm of clinical therapeutic drug monitoring of TKIs. Overall, the MonoTip C18 PT-SPE technique, coupled with LC-MS/MS, offers a formidable, eco-friendly, and effective strategy for the TDM of TKIs, marking a significant advancement in the field.

A novel fire-preventing composite gel, mainly made from steel slag (SS) and silica fume (SF), was created for a coal mine’s spontaneous combustion. The gelation mechanism of the steel slag-based composite gel (SSG) was investigated using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and field emission scanning electron microscopy (SEM). The findings suggest that SSG is generated through the processes of hydration and geopolymerization involving SS and SF. And in the alkaline milieu of a 1.5 M water glass solution, SSG manifests enhanced strength and water retention capacities. Moreover, the fire prevention and extinguishing performance of the SSG was analyzed and verified using low-temperature oxidation, thermogravimetry, and low temperature nitrogen adsorption experiment (LTNA). The SSG has proven highly effective in suppressing spontaneous coal combustion by inhibiting CO production, raising the coal oxidation temperature, and reducing the contact area between oxygen and the coal body.

The utilization of renewable solar energy for the photocatalytic transformation of carbon dioxide (CO₂) into valuable chemical substances is considered an optimal strategy to simultaneously address climate challenges and tackle energy scarcity. Herein, we prepared heterojunction photocatalysts UiO-66-NH₂/ZnIn₂S₄, which were successfully applied in the photocatalytic reduction of CO₂. The yield of the main product CO, for the optimal UiO-66-NH₂/ZnIn₂S₄-2 sample could reach up to 57 μmol g⁻¹h⁻¹ when converting CO₂ under the visible light irradiation, which was approximately 3.35 and 2.71 times higher than that achieved by the individual UiO-66-NH₂ and ZnIn₂S₄ samples, respectively. The better photocatalytic performance of the UiO-66-NH₂/ZnIn₂S₄-2 composites can be attributed to its synergistic effect resulting from tight interfacial contacts, special charge transfer pathways and excellent CO₂ adsorption capacity. Furthermore, the intimate contact between UiO-66-NH₂ and flower-like ZnIn₂S₄ accelerates electron transmission while effectively suppressing the quenching of photogenerated carriers. This research provides vital knowledge for the rational design of heterostructures aimed at enhancing the efficiency of CO₂ photocatalysis for solar fuel production.

Cyclodextrins (CDs) are essential compounds because of their wide applications in many fields. They are cyclic oligosaccharides with lipophilic internal cavities and hydrophilic external surfaces that link the α-D-glucopyranose portion. β-Cyclodextrin (β-CD) is a non-toxicity, cheap, green, and renewability macrocycle with excellent performance in organic transformation. β-CD is a green catalyst with satisfactory catalytic activity in diverse organic changes. Regarding green chemistry’s goals, β-CD opens the way to effective catalysts for various reactions. Heterocyclic compounds are among the most prominent organic compounds in numerous organic materials, pharmaceuticals, and natural products. Heterocyclic compounds are essential in pharmaceutical products and show different biological activities in multiple illnesses. Thus, there is a tendency to develop novel, green, and helpful syntheses of heterocyclic systems, which has been a big challenge in synthetic organic chemistry. Using β-CD as catalysts for synthesizing heterocyclic compounds makes the procedure milder, easier, and less toxic, making it an eco-friendly substitute compared to the reported approaches. This review underlines the applications of β-CD-based catalysts for synthesizing heterocyclic compounds covering 2019–2023. This study will be helpful to researchers in the investigation areas of organic synthesis, medicinal chemistry, synthetic materials, and pharmacological medicine..

The pervasive presence of mercury in water and cosmetics poses significant health risks, necessitating the development of a method for the in-situ monitoring and extraction of mercury ions. This study introduces a novel approach utilizing Mesoporous Silica Nanotubes (MSNTs) with a unique worm-like structure, providing an expansive surface area ideal for the adsorption of a Hg²⁺ ion chromophore, N,N,N,N′-Tetramethyl-4,4′-diaminobenzophenone. This configuration enables rapid and visible detection of toxic mercury, with a color transition from yellow to green that is easily discernible by the naked eye. The sensitivity of the Mercury nano-sensor (MNS) is remarkably high, with a detection limit of 1.9 × 10^-8 M as determined by digital image analysis, and 4.9 × 10^-8 M via spectrophotometric methods—both well below the WHO guidelines for drinking water. The MNS’s low detection threshold, coupled with its reusability after simple regeneration, positions it as an effective tool for preliminary water testing. The findings suggest that the MNS, requiring only 10 mg for measurements, offers a promising solution for the real-time visualization of mercury ions, enhancing safety measures in water and cosmetic products.